In recent years, the use of color ink-jet printers, color laser printers, and the like as color printers has become widespread. A color printer uses a color conversion lookup table to convert input color image data into amounts of plural inks. In the conventional method for creating a color conversion lookup table, (i) a plurality of color patches are printed, (ii) colors of the color patches are measured to obtain their colorimetric values, and (iii) a lookup table that represents correspondence relationships between color patch calorimetric values and the amounts of ink used to print the color patches is created.
However, calorimetric values are dependent upon viewing condition during color measurement. Accordingly, where a color conversion lookup table has been created so as to give a printout having good color reproduction under a certain viewing condition, it will not necessarily be the case that printouts created using that color conversion lookup table will afford good color reproduction under other viewing conditions. Accordingly, there has for some time existed a need for a color conversion lookup table able to give good color reproduction under various viewing conditions. There has also been a need, when creating a reproduction of a painting or drawing for example, to create a color conversion lookup table that can reproduce as faithfully as possible the color appearance of the original.
The image quality of a printout created using a color conversion lookup table is dependent in large degree to the calorimetric values and ink amounts specified in the color conversion lookup table. In practical terms, it is necessary for a color conversion lookup table to simultaneously afford good reproduction under various viewing conditions, and high image quality in printed output. According, there was a need to create a color conversion lookup table capable of afford good reproduction under various viewing conditions while at the same time printing with high image quality. Such requirements are not limited just to color conversion lookup tables, but are generally desirable in all manner of profiles used for color conversion.